Abstract - We investigated the possibility of feeding individual bees known amounts of pesticides on a standard artificial flower with or without scent. We tested experienced and naive (without foraging experience) Osmia lignaria and Megachile rotundata females, and experienced Apis mellifera foragers, and trained (exposed to the artificial flower for 24 h) and untrained individuals of the three species. We also fed untrained individuals of all three species with feeding units made with natural flowers (Ladurner et al., Apidologie 34 (2003) 597-602). Feeding success on artificial flowers was lower (0-50%) for O. lignaria and M. rotundata, than A. mellifera (70-97%). Training improved feeding success in O. lignaria and A. mellifera, but not M. rotundata. Experience improved feeding success in O. lignaria, but not M. rotundata. Scent had no effect on feeding success for any of the three species. Feeding success with the natural flower method was high for the three species (87-90%).